Circuit packages, such as systems on a chip, multi-chip modules, and integrated circuit packages, may include multiple voltage regulators. Each of these voltage regulators may produce a different voltage for powering respective different portions of their circuit packages during normal operation. For example, in some instances, a voltage regulator generating an output voltage in a first range may be used for powering memory cells, while a voltage regulator generating an output voltage in a second range may be used for powering CPU cores, and a voltage regulator generating an output voltage in a third range may be used for powering input/output circuits.
For testing of these circuit packages after fabrication (e.g. production testing), or by a customer (e.g. customer testing), it may be desirable to be able to disable the in-package voltage regulators so as to permit external supply voltages to be applied using a test tool.
Accordingly, the development of voltage regulator bypass circuitry usable in such circuit packages is necessary.